3.9.12

* Allow to close tabs via group tab pages (middle-click or closeboxes.)
* Reduce flicker while updating tab list in group tab pages.
* Accept multiple URLs for new tabs (to support new tabs on both regular and private browsing windows.)
* Better synchronization of loading throbbers ([by Lej77](https://github.com/piroor/treestyletab/pull/3269), thanks!)